Publication practices and standards: recommendations from GSK Vaccines' author survey

BACKGROUND

Evolving standards of good publication practice (GPP) and a survey conducted in 2009 of authors, who were investigators and researchers not employed by the company prompted changes to GSK Vaccines' publication practices. We conducted a follow-up survey in 2012 to assess the company's revised practices and to evaluate understanding of GPP among investigators and researchers who had previously authored at least one publication in collaboration with GSK Vaccines.

METHODS

The 50-question web-based survey addressed authoring practices and transparency of decision-making. Investigators and researchers (n = 1,273) who had authored at least one publication reporting on GSK Vaccines-sponsored human research since 2007, were invited to participate. Responses to 37 closed questions are presented. The remaining 13 questions were open-ended or did not concern publication practices.

RESULTS

A total of 415 external authors (32.6%) responded. International Committee of Medical Journal Editors (ICMJE) authorship criteria were clear to most respondents (78.1%); 7.7% found they were unclear. The majority of participants (86.8%) found GSK Vaccines' authorship questionnaire a suitable tool to assess eligibility for authorship as per the ICMJE criteria. However, only 68.5% felt that the outcome of the questionnaire is communicated appropriately and 58.3% felt well informed on changes in authorship. Nearly two-thirds (62.9%) of respondents felt that having a pharmaceutical company employee as lead author makes manuscript acceptance less likely. Access to relevant data was regarded as sufficient by 78.5% of respondents. Briefing meetings before publication start, publication steering committees and core writing teams were recognized as valuable publication practices. Professional medical writing support was seen as adding value to publication development by 87.7% of participants. Most respondents agreed that manuscript discussions should start early, with 81.7% stating that they were in favor of introducing a formalized 'author agreement' at the publication start.

CONCLUSIONS

GSK Vaccines made changes to its publication practices to ensure improved transparency and better involvement of external authors. The results of this survey suggest that these changes have been effective to a large extent. They confirm the need for effective and timely communication, as well as transparent processes for authorship and decision-making during publication development. The identified gaps in GPP will help to guide further improvements to the company's policies on publication practices.

Present and potential future issues in glioblastoma treatment

The treatment of glioblastomas requires a multidisciplinary approach that takes the presently incurable nature of the disease into consideration. Treatments are multimodal and include surgery, radiotherapy and chemotherapy. Current recommendations are that patients with glioblastomas should undergo maximum surgical resection, followed by concurrent radiation and chemotherapy with the novel alkylating drug temozolomide. This is then to be followed by additional adjuvant temozolomide for a period of up to 6 months. Major advances in surgical and imaging technologies used to treat glioblastoma patients are described. These technologies include magnetic resonance imaging and metabolic data that are helpful in the diagnosis and guiding of surgical resection. However, glioblastomas almost invariably recur near their initial sites. Disease progression usually occurs within 6 months and leads rapidly to death. A number of signaling pathways can be activated constitutively in migrating glioma cells, thus rendering these cells resistant to proapoptotic insults, such as conventional chemotherapies. Therefore, the molecular and cellular therapies and local drug delivery that could be used to complement conventional treatments are described, and some of the currently ongoing clinical trials are reviewed, with respect to these new approaches.

The characterization of nuclear-DNA content, the proliferative activity and the immunohistochemical expression of gfap, vim, leu-7, s-100, p53 and cathepsin-d in human glioblastoma multiformes (hgbms) versus human gbm cell-lines grafted into the brains of nude-mice

Experimental models relating to human glioblastoma multiformes (hGBMs) involve the intracranial or intracerebral injection of human GBM cells into nude mice or rats. The aim of the present study was to compare a number of biological characteristics of hGBMs as opposed to experimental GBMs obtained by grafting either human U87 or U373 glioblastoma cells into the brains of nude mice. Biological assessments involve four distinct sets of parameters, i.e. i) the determination of the nuclear DNA content, ii) the determination of proliferative activity, iii) the assessment of p53 nuclear phosphoprotein immunohistochemical reactivity, and iv) the assessment of GFAP, VIM, LEU-7, S-100 and CAT D protein immunohistochemical reactivity. While most of the human glioblastoma multiformes (hGBMs) under study were immunohistochemically reactive to GFAP, S-100, LEU-7 and VIM as indeed were the experimental U373 GBMs, the U87 ones were reactive to VIM only. Furthermore, the U87 GBMs appeared to be more aggressive than the U373 ones since the former were associated with a shorter tumor-bearing mouse survival time than the latter. Such aggressiveness was further associated with a proliferative activity and a cathepsin D immunoreactivity, both of which were markedly higher in the U87 GBMs than in the U373 GBMs. These two experimental GBM models also exhibited tumors which were predominantly diploid. The present study shows that it is possible to set up experimentally in vivo models which strongly mimic human glioblastoma multiformes. Such models consist of grafting human glioblastoma cell lines, namely U87 and U373, into the brains of nude mice. However, while it is true that experimental GBMs closely resemble the hGBMs with respect to some biological characteristics, they also differ in many other significant biological characteristics.

In-vitro characterization of dihydrotestosterone-induced, epidermal growth factor-induced and basic fibroblastic growth factor-induced modifications in the growth dynamics of the human prostate-cancer cell-line lncap, du145 and pc3

The influence of dihydrotestosterone (DHT), the epithelial growth factor (EGF) and the basic fibroblast growth factor (bFGF) was investigated on LNCaP, DU145 and PC3 cell growth, which represents the ratio between cell gain (cell proliferation) and cell loss (cell death). In the present study, cell growth was assessed by means of the computer-assisted microscope analysis of Feulgen-stained nuclei combined with the mathematical Delaunay triangulation and Voronoi paving techniques, which enabled the cell colony patterns, i.e. their density and level of organisation, to be determined. The results from a previous study (Janssen et al, Prostate, in press) combined with those of the present one show that DHT was found to activate proliferation of the LNCaP model, as evidenced by increase in size of colonies, increase in number of cells within colonies, increase in cell colony density and, accordingly, decrease in mean segment length value (which is the distance between adjacent cell nuclei). Using the same criteria, DHT was found inhibitory on growth of DU145 cell line, and devoid of significant effect on PC3 cell line. Basic FGF was found to be a powerful stimulator of growth of PC3 cell Line and to induce a weaker stimulation of DU145 cell line. On LNCaP cell line, it increased the size of colonies without increase of the number of cells per colony. This feature can be explained by a decrease in cell colony density. With respect to the same colonies, the proliferation index (percentage of cells in the S+G2 phases of the cell cycle) was found similar to that of the controls. This suggests that the increase in the size of the colonies is due to a difference of spreading of the cells on their supports. EGF had no significant effect on LNCaP and PC3 models, and was decreasing cell density of DU145 colonies.

Galectin-1 is implicated in the protein kinase C epsilon/vimentin-controlled trafficking of integrin-beta1 in glioblastoma cells

Cell motility and resistance to apoptosis characterize glioblastoma (GBM) growth and malignancy. In our current work we report that galectin‐1, a homodimeric adhesion molecule and carbohydrate‐binding protein with affinity for β‐galactosides, is linked with cell surface expression of integrin β1 and the process of integrin trafficking. Using immunofluorescence, depletion of galectin‐1 through both stable knockdown and transient‐targeted small interfering RNA (siRNA) treatment induces an intracellular accumulation of integrin‐β1 coincident with a diminution of integrin‐β1 at points of cellular adhesion at the cell membrane. Galectin‐1 depletion does not alter the gene expression level of integrin‐β1. Transient galectin‐1 depletion effectuates as well the perinuclear accumulation of protein kinase C epsilon (PKCε) and the intermediate filament vimentin, both of which have been shown to mediate integrin recycling in motile cells. Our results argue for the involvement of galectin‐1 in the PKCε/vimentin‐controlled trafficking of integrin‐β1. The understanding of molecular mediators such as galectin‐1 and the pathways through which they drive the cell invasion so descriptive of GBM is anticipated to reveal potential therapeutic targets that promote glioma malignancy.

Galectins as modulators of tumor progression in head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCCs) remain a significant cause of morbidity worldwide. Biological therapies able to induce and/or upregulate antitumor immune responses could represent a complementary approach to conventional treatments for patients with HNSCC because, despite advances in surgery, radiotherapy, and chemotherapy, the overall survival rates for these patients have not changed over recent decades. Galectins are involved in the control of cell proliferation, cell death, and cell migration and in the modulation of various functions of the immune system. In this context, galectin-1 is known to protect HNSCCs from the immune system. The present review details the involvement of galectins in HNSCC biology and suggests a number of approaches to reduce the levels of expression of galectin-1 in HNSCCs, with the aim of improving the efficiency of HNSCC immunotherapy.

High level of galectin-1 expression is a negative prognostic predictor of recurrence in laryngeal squamous cell carcinomas

Monitoring of gene-expression profiles is assumed to refine tumor characterization of laryngeal squamous cell carcinomas (LSCCs) with a therapeutic perspective. This is especially expected for adhesion/growth-regulatory effectors such as galectins, a class of endogenous lectins. Using computer-assisted microscopy, we investigated the prognostic value contributed by the quantitative determination of the immunohistochemical levels of expression of galectin-1, -3 and -7 in a series of 62 LSCCs including 42 low- and 20 high-stage LSCCs. As galectin-1 may have a key role leading to a tumor escape from immune surveillance, we also investigated whether or not the level of galectin-1 expression correlated with lymphocyte infiltration in LSCCs. The immunohistochemical determination of expression of galectin-1 is of prognostic value in human squamous laryngeal cancers. LSCCs that display high levels of galectin-1 have worse prognoses than laryngeal cancers with low levels of galectin-1 expression. Elevation of galectin-1 levels in laryngeal cancers can contribute to the process of tumor immune escape by killing the activated T-cells and other protumoral activities such as promoting motility or activity of oncogenic H-Ras proteins. The quantitative determination of galectin-1 in LSCCs is an independent prognostic marker when opposed to TNM staging. It has the potential to identify patients unlikely to benefit from T-cell-mediated immunotherapy, although the definitive effector function from its pro- and antitumoral activity profile has not been delineated.

Anti-galectin compounds as potential anti-cancer drugs

Galectins form a family of carbohydrate-binding proteins defined by their affinity for beta-galactosides containing glycoconjugates. The carbohydrate recognition domain (CRD) is responsible for the specificity of galectins for saccharides. This binding may result in modulated cell proliferation, cell death and cell migration, three processes that are intimately involved in cancer initiation and progression. Galectins can also display protein-protein types of interactions with their binding partners. Certain galectins directly involved in cancer progression seem to be promising targets for the development of novel therapeutic strategies to combat cancer. Indeed, migrating cancer cells resistant to apoptosis still constitute the principal target for the cytotoxic drugs used to treat cancer patients. Reducing the levels of migration in apoptosis-resistant cancer cells can restore certain levels of sensitivity to apoptosis (and so to pro-apoptotic drugs) in restricted-migration cancer cells. Anti-galectin agents can restrict the levels of migration of several types of cancer cell and should therefore be used in association with cytotoxic drugs to combat metastatic cancer. We provide experimental proof in support of this concept. While the present review focuses on various experimental strategies to impair cancer progression by targeting certain types of galectins, it pays particular attention to glioblastomas, which constitute the ultimate level of malignancy in primary brain tumors. Glioblastomas form the most common type of malignant brain tumor in children and adults, and no glioblastoma patient has been cured to date.

The in vitro influences of neurotensin on the motility characteristics of human U373 glioblastoma cells

Astrocytic tumours are associated with dismal prognoses due to their pronounced ability to diffusely invade the brain parenchyma. Various neuropeptides, including gastrin, are able to modulate tumour astrocyte migration. While neurotensin has been shown to influence the proliferation of glioma cells and the migratory ability of a large set of other cell types, its role in glioma cell migration has never been investigated. Neurotensin-induced modifications to the motility features of human U373 glioblastoma cells therefore constitute the topic of the present study. We evidenced that three subtypes of neurotensin receptors (NTR1, NTR2 and NTR3) are expressed in U373 glioblastoma cells, at least as far as their mRNAs are concerned. Treating U373 tumour cells with 10 nM neurotensin markedly modified the morphological patterns of these cells and also profoundly altered the organization of their actin cytoskeletons. Pull-down assays revealed that neurotensin induced the activation in U373 cells of both Rac1 and Cdc42 but not RhoA. Scratch wound assays evidenced that neurotensin (0.1 and 10 nM) very significantly inhibited wound colonization by U373 cells cultured in the absence of serum. In addition, quantitative phase-contrast videomicroscopy analyses showed that neurotensin decreases the motility levels of U373 glioblastoma cells when these cells are cultured on plastic. In sharp contrast, neurotensin stimulates the motility of U373 cells when they are cultured on laminin, which is a pro-adhesive extracellular matrix component ubiquitously secreted by glioma cells. Our data thus strongly suggest that, in addition to gastrin, neurotensin is a neuropeptide capable of modulating tumour astrocyte migration into the brain parenchyma.

Galectin-1: a small protein with major functions

Galectins are a family of carbohydrate-binding proteins with an affinity for beta-galactosides. Galectin-1 (Gal-1) is differentially expressed by various normal and pathological tissues and appears to be functionally polyvalent, with a wide range of biological activity. The intracellular and extracellular activity of Gal-1 has been described. Evidence points to Gal-1 and its ligands as one of the master regulators of such immune responses as T-cell homeostasis and survival, T-cell immune disorders, inflammation and allergies as well as host-pathogen interactions. Gal-1 expression or overexpression in tumors and/or the tissue surrounding them must be considered as a sign of the malignant tumor progression that is often related to the long-range dissemination of tumoral cells (metastasis), to their dissemination into the surrounding normal tissue, and to tumor immune-escape. Gal-1 in its oxidized form plays a number of important roles in the regeneration of the central nervous system after injury. The targeted overexpression (or delivery) of Gal-1 should be considered as a method of choice for the treatment of some kinds of inflammation-related diseases, neurodegenerative pathologies and muscular dystrophies. In contrast, the targeted inhibition of Gal-1 expression is what should be developed for therapeutic applications against cancer progression. Gal-1 is thus a promising molecular target for the development of new and original therapeutic tools.

Galectin 7 (p53-Induced Gene 1): A New Prognostic Predictor of Recurrence and Survival in Stage IV Hypopharyngeal Cancer

BACKGROUND

Eighty percent of hypopharyngeal squamous cell carcinoma patients have advanced stages (III and IV) of the disease, and biological markers are required to predict high-risk head and neck squamous cell carcinoma patients in need of highly aggressive treatments after surgery to improve the survival rate. We analyzed the potential prognostic value of galectin 7 in a series of 81 stage IV hypopharyngeal SCCs because galectin 7 is an emerging marker involved in the epidermal development of pluristratified epithelia and in epidermal cell migration.

METHODS

The immunohistochemical expression of galectin 7 was determined on a series of 81 stage IV hypopharyngeal SCCs and was compared with that of galectins 1 and 3.

RESULTS

High levels of galectin 7 expression were associated with rapid recurrence rates and dismal prognoses in these 81 stage IV hypopharyngeal SCCs, a feature not observed with galectin 3 and one observed weakly, if at all, with galectin 1.

CONCLUSIONS

These data suggest that the immunohistochemical determination of galectin 7 expression in the case of high-risk hypopharyngeal cancers is a meaningful tool to identify patients who should benefit from aggressive postsurgical adjuvant therapy after surgery, including not only radiotherapy, but also chemotherapy.

Supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas are characterized by a differential expression of S100 proteins

The levels of expression of the S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B proteins were immunohistochemically assayed and quantitatively determined in a series of 95 astrocytic tumors including 26 World Health Organization (WHO) grade I (pilocytic astrocytomas), 23 WHO grade II (astrocytomas), 25 WHO grade III (anaplastic astrocytomas) and 21 WHO grade IV (glioblastomas) cases. The level of the immunohistochemical expression of the S100 proteins was quantitatively determined in the solid tumor tissue (tumor mass). In addition twenty blood vessel walls and their corresponding perivascular tumor astrocytes were also immunohistochemically assayed for 10 cases chosen at random from each of the four histopathological groups. The data showed modifications in the level of S100A3 protein expression; these modifications clearly identified the pilocytic astrocytomas from WHO grade II-IV astrocytic tumors as a distinct biological group. Modifications in the level of S100A6 protein expression enabled a clear distinction to be made between low (WHO grade I and II) and high (WHO grade III and IV) grade astrocytic tumors. Very significant modifications occurred in the level of S100A1 protein expression (and, to a lesser extent, in their of the S100A4 and S100B proteins) in relation to the increasing levels of malignancy. While the S100A5 protein was significantly expressed in all the astrocytic tumors (but without any significant modifications in the levels of malignancy), the S100A2 protein was never expressed in these tumors. These data thus indicate that several S100 proteins play major biological roles in human astrocytic tumors.

Galectins are differentially expressed in supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas, and significantly modulate tumor astrocyte migration

Galectins, a family of mammalian lectins with specificity to beta-galactosides, are involved in growth-regulatory mechanisms and cell adhesion. A relationship is assumed to exist between the levels of expression of galectins and the level of malignancy in human gliomas. A comparative study of this aspect in the same series of clinical samples is required to prove this hypothesis. Using computer-assisted microscopy, we quantitatively characterized by immunohistochemistry the levels of expression of galectins-1, -3 and -8 in 116 human astrocytic tumors of grades I to IV. Extent of transcription of galectins-1, -3, and -8 genes was investigated in 8 human glioblastoma cell lines by means of RT-PCR techniques. Three of these cell lines were grafted into the brains of nude mice in order to characterize in vivo the galectins-1, -3 and -8 expression in relation to the patterns of the tumor invasion of the brain. The role of galectin-1, -3 and -8 in tumor astrocyte migration was quantitatively determined in vitro by means of computer-assisted phase-contrast videomicroscopy. The data indicate that the levels of galectin-1 and galectin-3 expression significantly change during the progression of malignancy in human astrocytic tumors, while that of galectin-8 remains unchanged. These three galectins are involved in tumor astrocyte invasion of the brain parenchyma since their levels of expression are higher in the invasive parts of xenografted glioblastomas than in their less invasive parts. Galectin-3, galectin-1, and to a lesser extent galectin-8, markedly stimulate glioblastoma cell migration in vitro. Since bands for the transcripts of human galectins-2, -4 and -9 were apparently less frequent and intense in the 8 human glioblastoma cell lines, this system provides an excellent model to assign defined roles to individual galectins and delineate overlapping and distinct functional aspects.

Improving morphology-based malignancy grading schemes in astrocytic tumors by means of computer-assisted techniques

We propose an original methodology which improves the accuracy of the prognostic values associated with conventional morphologically-based classifications in supratentorial astrocytic tumors in the adult. This methodology may well help neuropathologists, who must determine the aggressiveness of astrocytic tumors on the basis of morphological criteria. The proposed methodology comprises two distinct steps, i.e. i) the production of descriptive quantitative variables (related to DNA ploidy level and morphonuclear aspects) by means of computer-assisted microscopy and ii) data analysis based on an artificial intelligence-related method, i.e. the decision tree approach. Three prognostic problems were considered on a series of 250 astrocytic tumors including 39 astrocytomas (AST), 47 anaplastic astrocytomas (ANA) and 164 glioblastomas (GBM) identified in accordance with the WHO classification. These three problems concern i) variations in the aggressiveness level of the high-grade tumors (ANA and GBM), ii) the detection of the aggressive as opposed to the less aggressive low-grade astrocytomas (AST), and iii) the detection of the aggressive as opposed to the less aggressive anaplastic astrocytomas (ANA). Our results show that the proposed computer-aided methodology improves conventional prognosis based on conventional morphologically-based classifications. In particular, this methodology enables some reference points to be established on the biological continuum according to the sequence AST-->ANA-->GBM.

Galectin-1 knocking down in human U87 glioblastoma cells alters their gene expression pattern

We have previously reported that (i) progression of malignancy in patients bearing astrocytic tumors correlates with increased tumor levels of galectin-1; (ii) in vitro addition of purified galectin-1 to U87 human glioblastoma cells enhances tumor cell motility; and (iii) conversely, knocking down galectin-1 expression in this cell line by stable transfection with antisense galectin-1 mRNA impairs motility and delays mortality after their intracranial grafting to nude mice. We here used cDNA microarray analysis to compare the effect on gene expression of stable transfection with antisense galectin-1 vector to mock-transfected and wild-type cells. Among the 631 spots probing genes potentially involved in cancer that were valid for analysis on all the arrays the expression of 86 genes was increased at least 2-fold. Confirmation of increased protein levels was provided by immunocytochemistry for p21waf/cip1, cullin-2, p53, ADAM-15, and MAP-2. Major differences in the expression patterns of ADAM-15 and the actin stress fiber organization were also observed. U87 cells stably deficient for galectin-1 expression were significantly less motile than control. We conclude that the stable inhibition of galectin-1 expression alters the expression of a number of genes that either directly or indirectly influence adhesion, motility and invasion of human glioblastoma cells.

Combined cimetidine and temozolomide, compared with temozolomide alone: significant increases in survival in nude mice bearing U373 human glioblastoma multiforme orthotopic xenografts

OBJECT

Malignant gliomas consist of both heterogeneous proliferating and migrating cell subpopulations, with migrating glioma cells exhibiting less sensitivity to antiproliferative or proapoptotic drugs than proliferative cells. Therefore, the authors combined cimetidine, an antiinflammatory agent already proven to act against migrating epithelial cancer cells, with temozolomide to determine whether the combination induces antitumor activities in experimental orthotopic human gliomas compared with the effects of temozolomide alone.

METHODS

Cimetidine added to temozolomide compared with temozolomide alone induced survival benefits in nude mice with U373 human glioblastoma multiforme (GBM) cells orthotopically xenografted in the brain. Computer-assisted phase-contrast microscopy analyses of 9L rat and U373 human GBM cells showed that cimetidine significantly decreased the migration levels of these tumor cells in vitro at concentrations at which tumor growth levels were not modified (as revealed on monotetrazolium colorimetric assay). Computer-assisted microscope analyses of neoglycoconjugate-based glycohistochemical staining profiles of 9L gliosarcomas grown in vivo revealed that cimetidine significantly decreased expression levels of endogenous receptors for fucose and, to a lesser extent, for N-acetyl-lactosamine moieties. Endogenous receptors of this specificity are known to play important roles in adhesion and migration processes of brain tumor cells.

CONCLUSIONS

Cimetidine, acting as an antiadhesive and therefore an antimigratory agent for glioma cells, could be added in complement to the cytotoxic temozolomide compound to combat both migrating and proliferating cells in GBM.

A model-based approach for automated in vitro cell tracking and chemotaxis analyses

BACKGROUND

Chemotaxis may be studied in two main ways: 1) counting cells passing through an insert (e.g., using Boyden chambers), and 2) directly observing cell cultures (e.g., using Dunn chambers), both in response to stationary concentration gradients. This article promotes the use of Dunn chambers and in vitro cell-tracking, achieved by video microscopy coupled with automatic image analysis software, in order to extract quantitative and qualitative measurements characterizing the response of cells to a diffusible chemical agent.

METHODS

Previously, we set up a videomicroscopy system coupled with image analysis software that was able to compute cell trajectories from in vitro cell cultures. In the present study, we are introducing a new software increasing the application field of this system to chemotaxis studies. This software is based on an adapted version of the active contour methodology, enabling each cell to be efficiently tracked for hours and resulting in detailed descriptions of individual cell trajectories. The major advantages of this method come from an improved robustness with respect to variability in cell morphologies between different cell lines and dynamical changes in cell shape during cell migration. Moreover, the software includes a very small number of parameters which do not require overly sensitive tuning. Finally, the running time of the software is very short, allowing improved possibilities in acquisition frequency and, consequently, improved descriptions of complex cell trajectories, i.e. trajectories including cell division and cell crossing.

RESULTS

We validated this software on several artificial and real cell culture experiments in Dunn chambers also including comparisons with manual (human-controlled) analyses.

CONCLUSIONS

We developed new software and data analysis tools for automated cell tracking which enable cell chemotaxis to be efficiently analyzed.

v-Src accelerates spontaneous motility via phosphoinositide 3-kinase, phospholipase C and phospholipase D, but abrogates chemotaxis in Rat-1 and MDCK cells

In Rat-1 fibroblasts, v-Src causes a profound remodelling of cortical actin cytoskeleton. This transformation includes membrane ruffling, a hallmark of the leading edge in migrating cells, and results from activation of phosphoinositide 3-kinase (PI 3-kinase), phospholipase C (PLC) and phospholipase D (PLD). We therefore reexamined whether motility is constitutively triggered by v-Src and studied whether this response is controlled by the same signalling pathway. The study was performed using Rat-1/tsLA29 and MDCK/tsLA31 cells, each harbouring a different thermosensitive v-Src kinase, active at 34 degrees C but inactivated at 40 degrees C. In both cell lines, overnight v-Src activation induced transformation and accelerated spontaneous motility by approximately twofold, as evidenced by wound-healing assay and by single-cell track, time-lapse recording in Dunn chambers. Inhibitors of PI 3-kinase, PLC and PLD selectively abrogated acceleration of motility by v-Src. Since mechanisms that co-ordinate spontaneous, as distinct from oriented, cell migration are separable, we further analysed in Dunn chambers chemotactic response of Rat-1/tsLA29 cells to PDGF and of MDCK/tsLA31 cells to EGF. In both cases, v-Src decreased the steady-state level of growth factor receptors at the cell surface twofold, and abrogated movement directionality at comparable level of occupancy as in non-transformed cells. The burst of pinocytosis in response to growth factors was also abolished by v-Src. Altogether, these results indicate that v-Src triggers motility in a PI 3-kinase-, PLC- and PLD-dependent manner, but abrogates directionality by suppressing polarised signalling downstream of growth factor receptors.

The infrared spectrum of human glioma cells is related to their in vitro and in vivo behavior

The present research investigates whether infrared spectra can be related to the biological characteristics of glioma cell lines. We used nine human glioma cell lines for which a series of in vitro and in vivo biological features had already been established [Glia 36 (2001) 375] and were able to show that their characteristic infrared spectra reflect their in vitro migration (i.e., motility and invasiveness) properties and their in vivo aggressiveness. More particularly, the infrared data evidenced correlations at the level of the lipid/protein ratio. These relationships were found to be tissue-dependent when controlled on seven pancreatic carcinoma cell lines. We also showed that oligodendroglial and astrocytic tumor cells, whose identification remains difficult, can easily be identified by their infrared spectra in the lipid acyl chain region as well as in the nucleic acid region. We concluded that infrared spectroscopy could usefully complement information provided by more conventional diagnostic and prognostic (e.g., morphological and molecular) approaches.

Up-regulation of galectin-3 and its ligands by Trypanosoma cruzi infection with modulation of adhesion and migration of murine dendritic cells

The impact of a pathogen-induced inflammatory response on dendritic cells (DCs) and on their expression of galectin-3 (Gal-3) was studied on splenic DCs (sDCs) from Trypanosoma cruzi-infected mice. We determined the lectin expression and also presentation of ligands using the labeled galectin as probe. By reverse transcriptase polymerase chain reaction, western blot analysis, quantitative glycocytochemistry, and computer-assisted quantitative microscopy, we demonstrate that, in sDCs from infected mice, expression of Gal-3 and Gal-3-specific ligands were markedly up-regulated and adhesiveness was increased with Gal-3-coated substratum. Gal-3 expression was also enhanced in T. cruzi-infected D2SC-1 cells. To assess influence on migration, we had to work exclusively with D2SC-1 cells because sDCs rapidly lost their capacity to adhere to substratum. Migration of infected- and TCM-treated D2SC-1 cells were reduced when substratum was coated with Gal-3. Expression of Gal-3 by D2SC-1 was reduced when they were incubated with anti-Gal-3 antisense oligonucleotide without effect on cell invasion by the parasite. By using seven neoglycoconjugates, we probed the cellular capacity to specifically bind carbohydrate ligands. Similar to Gal-3, an up-regulation was noted with respect to sites specific for Man and alpha-GalNAc, respectively, revealing that infection-dependent changes are not confined to Gal-3-dependent parameters. Considered together, these data document for the first time that a parasitic infection can modulate both in vivo and in vitro the expression of Gal-3 and of ligands for this lectin in DCs with functional consequences on their capacities of adhesion and migration. These results suggest a new immunomodulatory property of T. cruzi.

Glycohistochemical characterization of vascular muscle cell destruction in CADASIL subjects by lectins, neoglycoconjugates and galectin-specific antibodies

CADASIL (Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a type of small-artery stroke and vascular dementia-inducing pathology of the brain. In order to explain the molecular mechanisms behind the alterations to the blood vessels in CADASIL subjects, we scrutinized the expression of glycan and glycan-binding sites in the wall of vessels taken from five such subjects (vs. five control subjects matched for age and sex). Specimens were taken from the brain, heart, kidney, liver and lung. Although the main vessel lesions were observed in the tissues depending on the blood-brain barrier, alterations to systemic vessels were also observed despite the absence of any symptoms. The histochemical expression of a panel of 10 biotinylated neoglycoconjugates [Gal-beta(1-4)-D-Glc, Galbeta(1-3)GalNAc, alpha-D-GalNAc, beta-D-GalNAc, GalNAcalpha(1-3)-D-GalNAcalpha, GalNAcalpha(1-3)-D-GalNAcbeta, beta-D-Glc, alpha-D-Man, l-Fucose and D-Glcalpha(1-4)-D-Glc], eight plant lectins (PNA, MAA, SNA, DBA, WGA, ConA, GNA and UEA-1) and two antigalectin antibodies was monitored by means of semiquantitative and quantitative computer-assisted microscopy. The data show the altered histochemical binding of plant lectins, such as UEA-1 and ConA, in the vessel walls of CADASIL subjects. The present work, based upon staining by a panel of neoglycoconjugates, provides a biochemical characterization of the alteration of vessel walls in the brain compared to other organs including the heart, kidney, lung and liver in CADASIL as opposed to control subjects. These glycohistochemical results suggest a functional relevance of protein-carbohydrate interactions in this disease.

Effect of hydrophilic components of the extracellular matrix on quantifiable diffusion-weighted imaging of human gliomas: preliminary results of correlating apparent diffusion coefficient values and hyaluronan expression level

OBJECTIVE

The purpose of this study was to evaluate the relationship between apparent diffusion coefficient (ADC) measured by MR imaging and the level of immunohistochemical expression of hyaluronan or hyaluronic acid as one of the main hydrophilic components of the extracellular matrix in brain glial tumors.

MATERIALS AND METHODS

Nineteen patients with primary glial brain tumors were included in the study. Mean ADC values were calculated in all tumors and were normalized with the ADC values of the contralateral normal-appearing brain ratios. All tumors underwent surgical resection, and the histologic diagnosis was based on the analysis of the surgical specimen. Mean values of the labeling index of hyaluronan (LI-HA) were calculated to determine quantifiably the histochemical expression of hyaluronan in the tumor. The mean ADC values and the mean ADC ratios (ADC(ratio)) of the tumors were then correlated to the mean values of the LI-HA.

RESULTS

The mean ADC (93 x 10(-5) mm(2)/sec) and the mean ADC(ratio) (1.25) of the high-grade glial tumors were significantly lower than the mean ADC (123 x 10(-5) mm/sec) and the mean ADC(ratio) (1.64) of the low-grade glial tumors (p < 0.01). The mean LI-HA (72.8%) was also significantly lower in the high-grade gliomas than the mean LI-HA (93.4%) in the low-grade gliomas (p < 0.001). A positive correlation was found between mean ADC values and the mean LI-HA (tau = 0.35, p < 0.05) and also between the mean ADC(ratio) and the mean LI-HA (tau = 0.33, p < 0.05).

CONCLUSION

Hyaluronan as one of the main hydrophilic components of the extracellular matrix in gliomas likely contributes to differences in the ADC values between high- and low-grade glial tumors.

Binding sites for Lewis antigens are expressed by human colon cancer cells and negatively affect their migration

In colon cancer, endothelial cell selectins can promote tumor cell attachment via interactions with sialylated Lewis antigens present at the surface of tumor cells, thereby facilitating tumor cell arrest and transmigration into the extravascular space. However, it is not known whether Lewis antigens interact with colon tumor cells and modify their migration. Our aim was to detect the presence of binding sites on human tumor cells for Lewis(a/x) antigens and their sialylated derivatives in vitro and in vivo and to analyze their influence on migration of colon cancer cells. The immunocytochemical and histochemical levels of expression of the four Lewis antigens were quantitatively determined in four human colon cancer cell lines and in in vivo nude mice xenografts. The levels of expression of specific binding sites for these sugar epitopes were determined by synthetic neoglycoconjugates. The influence of binding of these carbohydrate ligands on cancer cell migration was quantitatively evaluated by computer-assisted phase-contrast videomicroscopy performed on Matrigel culture supports either left uncoated or coated with neoglycoconjugate presenting synthetic Lewis(a), sialyl Lewis(a), Lewis(x), or sialyl Lewis(x) antigens. The influence of the calcium concentration in the culture medium on the Lewis antigen-mediated effects was checked. Human colon cancer cells expressed significant amounts of specific binding sites detected by the synthetic probes in addition to the oligosaccharide epitopes. The expression levels differed considerably between the four cell lines and between in vitro and in vivo specimens. Cell migration analysis revealed that the four Lewis antigens markedly decreased the levels of migration of the HCT-15 and LoVo cancer cells. This effect depends on the calcium concentration in the culture medium. Binding sites for Lewis epitopes are present on colon cancer cells. The functional relevance of these sites is indicated by the negative influence on cell migration of a matrix containing the oligosaccharides as ligand parts.

Upregulation of galectins-1 and -3 in human colon cancer and their role in regulating cell migration

To probe the potential contribution of beta-galactoside-contributing epitopes and receptor proteins (gal-1 and gal-3) to colon malignancy, we first examined the expression of galectins and binding sites in clinical specimens by lectin and immunohistochemistry. Sixty-seven colonic surgical resections were studied, including 10 normal, 10 mild dysplasias, 10 severe dysplasias and 37 cancers. gal-1 and gal-3 were expressed in variable amounts in the epithelial cells and the connective tissue of normal colon. Their expression significantly increased with the degree of dysplasia, suggesting that gal-1 and gal-3 and their binding sites are related to malignant progression, while gal-8 has been associated with suppressor activity. To study the functional aspects, the influence of these galectins on the migration of 4 human colorectal cancer cell lines (HCT-15, LoVo, DLD-1, CoLo201) was studied. In agreement with histopathologic monitoring, these tumor cells were found to produce gal-3, while only CoLo201 was positive for gal-1. Except for DLD-1 and gal-1, the lines exhibited gal-1 binding sites on the surface, prompting study by computer-assisted videomicroscopy of the effect on cell migration of the presence of galectin on the culture substrate. The level of cell migration for HCT-15, LoVo and CoLo201 cells was significantly reduced by 0.15 microg/cm(2) gal-1, and the presence of a blocking antibody at least reduced this effect. gal-3 significantly reduced cell migration in all 4 of the in vitro cell lines.

Galectins and cancer

The galectins are a family of proteins that are distributed widely in all living organisms. All of them share galactose-specificity. At present, 14 members of the family are characterized in mammals. The galectins have been implicated in many essential functions including development, differentiation, cell-cell adhesion, cell-matrix interaction, growth regulation, apoptosis, RNA splicing, and tumor metastasis. Although efforts have mostly focused on the possible function of galectins in tumor development and invasiveness, their precise role in this field is still debated. This review discusses the recent way in which the expression of galectins and galectin-binding sites may affect the behavior of a variety of human neoplastic tissues.

Gastrin significantly modifies the migratory abilities of experimental glioma cells

Malignant astrocytic tumors are characterized by the pronounced and diffuse migration of tumor astrocytes into the brain parenchyma. The present study shows that gastrin is a brain neuropeptide that is able to significantly modulate astrocytic tumor migration at both invasion and motility levels. In the matter of invasion, gastrin severely reduces the in vitro invasive abilities of C6 rat glioma, 9L rat gliosarcoma, and U373 human glioma cells in a collagen matrix. In vitro, gastrin also markedly modifies the motility features in both C6 and U373 cells, at least partly through a decrease in the expression of the RhoA small GTPase, and so brings about some dramatic modifications to the organization in the actin cytoskeleton. The in vitro preincubation of C6 tumor cells with gastrin significantly increases the life spans of rats stereotactically implanted with these cells as compared with the survival periods of rats implanted with gastrin-untreated C6 cells. As suggested by our in vitro experiments, these effects, observed in vivo cannot relate to only the gastrin-induced decrease in tumor astrocyte migratory abilities. Indeed, gastrin also induces immunomodulatory effects, because we observed a marked gastrin-induced recruitment of lymphocytes into C6 gliomas and 9L gliosarcomas. These data all suggest that gastrin can act as an endogenous modulator of glioma progression.

Evaluation of the efficiency of chemotherapy in in vivo orthotopic models of human glioma cells with and without 1p19q deletions and in C6 rat orthotopic allografts serving for the evaluation of surgery combined with chemotherapy

BACKGROUND

Malignant gliomas of the central nervous system remain associated with dismal prognoses because of their diffuse invasion of the brain parenchyma. Very few experimental models that mimic clinical reality are available today to test potentially new therapies. The authors set up experimental in vivo glioma models of anaplastic astrocytomas of human and rat origins and anaplastic oligodendroglioma of human origin. Standard hospital chemotherapies were employed to test the validity of these models.

METHODS

Three glioma cells lines obtained from the American Type Culture Collection (i.e., human Hs683 and U373 cells and rat C6 cells) were implanted into nude mouse brains (Hs683 and U373 cells) and rat brains (C6 cells). The astrocytic nature, as opposed to the oligodendrocytic nature, of the Hs683 and U373 models was investigated by using quantitative (computer-assisted microscopy) immunohistochemical characterizations of nestin, vimentin, glutathione-S-transferase alpha (GSTalpha), GSTmu, GSTpi, and p53 expression. Comparative genomic hybridization (CGH) was employed to investigate 1p19q losses. Chronic administrations of carmustine (BCNU), fotemustin, or temozolomide were assayed in the xenografted U373 and Hs683 models. Both BCNU-related chemotherapy and surgery were assayed in the C6 model.

RESULTS

The quantitative phenotypic analyses pointed to the oligodendroglial nature of the Hs683 cell line and the astrocytic nature of the U373 cell line. The Hs683 cells exhibited 1p19q losses, whereas the U373 cells did not. BCNU, fotemustin, and temozolomide dramatically increased the time of survival of the Hs683 oligodendroglioma-bearing mice, whereas temozolomide only induced a weak but nevertheless statistically significant increase in the U373 glioma-bearing mice. In the C6 rat glioma model, surgery and BCNU chemotherapy were more efficient than either treatment alone.

CONCLUSIONS

The in vivo models of gliomas of the central nervous system developed in the current work best mimicked clinical reality. They can be used either to identify new therapies against human gliomas or to optimize existing therapies.

Galectin-1 modulates human glioblastoma cell migration into the brain through modifications to the actin cytoskeleton and levels of expression of small GTPases

We show that high-grade astrocytic tumors with high levels of galectin-1 expression are associated with dismal prognoses. The immunohistochemical analysis of galectin-1 expression of human U87 and U373 glioblastoma xenografts from the brains of nude mice revealed a higher level of galectin-1 expression in invasive areas rather than non-invasive areas of the xenografts. Nude mice intracranially grafted with U87 or U373 cells constitutively expressing low levels of galectin-1 (by stable transfection of an expression vector containing the antisense mRNA of galectin-1) had longer survival periods than those grafted with U87 or U373 cells expressing normal levels of galectin-1. Galectin-1 added to the culture media markedly and specifically increased cell motility levels in human neoplastic astrocytes. These effects are related to marked modifications in the organization of the actin cytoskeleton and the increase in small GTPase RhoA expression. All the data obtained indicate that galectin-1 enhances the migratory capabilities of tumor astrocytes and, therefore, their biological aggressiveness.

C-terminal heptapeptide of gastrin inhibits astrocytomas motility by interacting with a new gastrin binding site

It is well known that the amidated C-terminal part of gastrin is crucial for its interaction with the classical seven transmembrane domain receptors CCK-1 or CCK-2. Nevertheless, over the past 10 years, several groups have characterized new binding sites using peptides related to gastrin (particularly glycine-extended forms of gastrin) on various tumoral and nontumoral cell lines. In the present study, we focused on the human astrocytic tumoral cell line U373. Although it has been described that gastrin was able to inhibit the motility of these cells, we were unable to detect any classical CCK/gastrin receptor. On the other hand, by using the radiolabeled C-terminal heptapeptide of gastrin ((125)I-G-7), we evidenced a new binding site that possessed a pharmacological profile different from the classical CCK/gastrin receptors. This new gastrin binding site seemed to be coupled to G proteins and be implicated in c-Fos transcription gene. Moreover, we showed that G-7 was able to induce a strong inhibition of U373 cell migration, a crucial biological effect when we know that astrocytoma cells' migration in brain parenchyma constitutes a major feature of malignancy in astrocytic tumors.

Galectin-8 expression decreases in cancer compared with normal and dysplastic human colon tissue and acts significantly on human colon cancer cell migration as a suppressor

BACKGROUND AND AIMS

Galectins are beta-galactoside binding proteins. This ability may have a bearing on cell adhesion and migration/proliferation in human colon cancer cells. In addition to galectins-1 and -3 studied to date, other members of this family not investigated in detail may contribute to modulation of tumour cell features. This evident gap has prompted us to extend galectin analysis beyond the two prototypes. The present study deals with the quantitative determination of immunohistochemical expression of galectin-8 in normal, benign, and malignant human colon tissue samples and in four human colon cancer models (HCT-15, LoVo, CoLo201, and DLD-1) maintained both in vitro as permanent cell lines and in vivo as nude mice xenografts. The role of galectin-8 (and its neutralising antibody) in cell migration was investigated in HCT-15, LoVo, CoLo201, and DLD-1 cell lines.

METHODS

Immunohistochemical expression of galectin-8 and its overall ability to bind to sugar ligands (revealed glycohistochemically by means of biotinylated histochemically inert carrier bovine serum albumin with alpha- and beta-D-galactose, alpha-D-glucose, and lactose derivatives as ligands) were quantitatively determined using computer assisted microscopy. The presence of galectin-8 mRNA in the four human colon cancer cell lines was examined by reverse transcriptase-polymerase chain reaction. In vitro, cellular localisation of exogenously added galectin-8 in the culture media of these colon cancer cells was visualised by fluorescence microscopy. In vitro galectin-8 mediated effects (and the influence of its neutralising antibody) on migration levels of living HCT-15, LoVo, CoLo201, and DLD-1 cells were quantitatively determined by computer assisted phase contrast microscopy.

RESULTS

A marked decrease in immunohistochemical expression of galectin-8 occurred with malignancy development in human colon tissue. Malignant colon tissue exhibited a significantly lower galectin-8 level than normal or benign tissue colon cancers; those with extensive invasion capacities (T3-4/N+/M+) harboured significantly less galectin-8 than colon cancers with localised invasion capacities (T1-2/N0/M0). The four experimental models (HCT-15, LoVo, CoLo201, and DLD-1) had more intense galectin-8 dependent staining in vitro than in vivo. Grafting the four experimental human colon cancer models onto nude mice enabled us to show that the immunohistochemical expression of galectin-8 was inversely related to tumour growth rate. In vitro, galectin-8 reduced the migration rate of only those human experimental models (HCT-15 and CoLo201) that exhibited the lowest growth rate in vivo.

CONCLUSIONS

Expression of galectin-8 correlated with malignancy development, with suppressor activity, as shown by analysis of clinical samples and xenografts. In vitro, only the two models with low growth rates were sensitive to the inhibitory potential of this galectin. Future investigations in this field should involve fingerprinting of these newly detected galectins, transcending the common focus on galectins-1 and -3.

Molecular characterization of cell substratum attachments in human glial tumors relates to prognostic features

Glioma cell attachments to substratum play crucial roles in the invasion by glioma cells of normal brain tissue. These attachments are mediated through interactions between extracellular matrix (ECM) components, integrins, focal adhesion-linked molecules, and the actin cytoskeleton. In the present study, we investigate the molecular elements involved in cell substratum attachments in human glial tumors and their potential relationships to prognostic features. We used 10 human glioma cell lines, for which we characterized glial differentiation by means of quantitative RT-PCR for nestin, vimentin, and GFAP mRNA. We quantitatively determined the amounts of laminin, fibronectin, vitronectin, and thrombospondin secreted by these glioma cell lines in vitro, as well as the amount of each of the eight beta integrin subunits and the adhesion complex-related molecules, including talin, vinculin, profilin, zyxin, alpha-actinin, paxillin, and VASP. After quantification of the levels of migration and invasion of these 10 cell lines in vitro and, through grafts into the brains of nude mice, of their biological aggressiveness in vivo, it appeared that the levels of the beta 5 integrin subunit and alpha-actinin were directly related to biological aggressiveness. These experimental data were clinically confirmed because increasing immunohistochemical amounts of the beta 5 integrin subunit and alpha-actinin were directly related to dismal prognoses in the case of astrocytic tumors. In addition, we show that the beta 4 integrin subunit are expressed significantly more in oligodendrogliomas than in astrocytic tumors. A potential role for the beta 8 integrin subunit in glioma cell substratum attachments is also emphasized.

Gastrin induces over-expression of genes involved in human U373 glioblastoma cell migration

Astrocytic tumors are the most common and the most malignant primary tumors of the central nervous system. We had previously observed that gastrin could significantly modulate both cell proliferation and migration of astrocytoma cells. We have investigated in the present study which genes could be targeted by gastrin in tumor astrocyte migration. Using a subtractive hybridization PCR technique we have cloned genes differentially over-expressed in human astrocytoma U373 cells treated or not with gastrin. We found about 70 genes over-expressed by gastrin. Among the genes overexpressed by gastrin, we paid particular attention to tenascin-C, S100A6 and MLCK genes because their direct involvement in cell migration features. Their gastrin-induced overexpression was quantitatively determined by competitive RT-PCR technique. We also showed by means of a reporter gene system that S100A6 and tenascin-C respective promoters were upregulated after gastrin treatment. These data show that gastrin-mediated effects in glioblastoma cells occur through activation of a number of genes involved in cell migration and suggest that gastrin could be a target in new therapeutic strategies against malignant gliomas.

S100A2, a putative tumor suppressor gene, regulates in vitro squamous cell carcinoma migration

It has been previously shown that S100A2 is down-regulated in tumor cells and can be considered a tumor suppressor. We have recently shown that this down-regulation can be observed particularly in epithelial tissue, where S100A2 expression decreases remarkably in tumors as compared with normal specimens. In the present paper we investigate whether S100A2 could play a tumor-suppressor role in certain epithelial tissues by acting at the cell migration level. To this end, we made use of five in vitro human head and neck squamous cell carcinoma lines in which we characterized S100A2 expression at both RNA and protein level. To characterize the influence of S100A2 on cell kinetic and cell motility features, we used two complementary approaches involving specific antisense oligonucleotides and the addition of S100A2 to the culture media. The different expression analyses gave a coherent demonstration of the fact that the FADU and the RPMI-2650 cell lines exhibit high and low levels of S100A2 expression, respectively. Antisense oligonucleotides (in FADU) and extracellular treatments (in RPMI) showed that, for these two models, S100A2 had a clear inhibitory influence on cell motility while modifying the cell kinetic parameters only slightly. These effects seem to be related, at least in part, to a modification in the polymerization/depolymerization dynamics of the actin microfilamentary cytoskeleton. Furthermore, we found evidence of the presence of the receptor for advanced glycation end-products (RAGE) in RPMI cells, which may act as a receptor for extracellular S100A2. The present study therefore presents experimentally based evidence showing that S100A2 could play a tumor-suppressor role in certain epithelial tissues by restraining cell migration features, at least in the case of head and neck squamous cell carcinomas.

Galectin-1 is highly expressed in human gliomas with relevance for modulation of invasion of tumor astrocytes into the brain parenchyma

Protein (lectin)-carbohydrate interaction is supposed to be relevant for tumor cell behavior. The aims of the present work are to investigate whether galectin-1 modulates migration/invasion features in human gliomas in vitro, whether it can be detected in human gliomas immunohistochemically, and whether its expression is attributable to certain glioma subgroups with respect to invasion and prognosis. For this purpose, we quantitatively determined (by computer-assisted microscopy) the immunohistochemical expression of galectin-1 in 220 gliomas, including 151 astrocytic, 38 oligodendroglial, and 31 ependymal tumors obtained from surgical resection. We also xenografted three human glioblastoma cell lines (the H4, U87, and U373 models) into the brains of nude mice in order to characterize the in vivo galectin-1 expression pattern in relation to tumor invasion of the normal brain parenchyma. In addition, we characterized the role in vitro of galectin-1 in U373 tumor astrocyte migration and kinetics. Our data reveal expression of galectin-1 in all human glioma types with no striking differences between astrocytic, oligodendroglial, and ependymal tumors. The level of galectin-1 expression correlated with the grade in the group of astrocytic tumors only. Furthermore, immunopositivity of high-grade astrocytic tumors from patients with short-term survival periods was stronger than that of tumors from patients with long-term survivals. In human glioblastoma xenografts, galectin-1 was preferentially expressed in the more invasive parts of these xenografts. In vitro experiments revealed that galectin-1 stimulates migration of U373 astrocytes.

Distinct differences in binding capacity to saccharide epitopes in supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas, and glioblastomas

We monitored the expression of glycan-binding sites on a panel of 10 biotinylated neoglycoconjugates by means of quantitative computer-assisted microscopy to further study the molecular mechanisms in the extensive infiltration of the surrounding brain parenchyma by most astrocytic tumors. Three distinct histological compartments were analyzed for each of the 108 astrocytic tumors (15 pilocytic astrocytomas (WHO grade I), 25 astrocytomas (WHO grade II), 30 anaplastic astrocytomas (WHO grade III), and 38 glioblastomas (WHO grade IV) included in our series. These compartments were tumors (nonperivascular tumor astrocytes), perivascular tumor astrocytes, and blood vessel walls. Clear differences were observed between the pilocytic and the diffuse astrocytic tumors. Furthermore, malignant progression in the latter category was paralleled by a decrease in cells' ability to bind distinct sugar epitopes, especially the D-GalNAc(alpha1-3)-D-GalNAc-beta1-R determinant of the Forssman pentasaccharide in tumors, the alpha-L-fucose in perivascular tumor areas, and the beta-D-glucose in tumor vessel walls. Markedly, the level of binding site expression for alpha-D-mannose decreased in the tumors, the perivascular tumor areas, and the vessel walls. These glycohistochemical results imply the functional relevance of protein-carbohydrate interactions in this tumor system.

Differential expression of S100 calcium-binding proteins characterizes distinct clinical entities in both WHO grade II and III astrocytic tumours

The computer-assisted microscopic analysis of Feulgen-stained nuclei enabled us to identify two subgroups of astrocytomas (WHO grade II) and two subgroups of anaplastic astrocytomas (WHO grade III) with significantly distinct clinical outcomes (Decaestecker et al. Brain Pathol 1998; 8: 29-38). The astrocytomas labelled in the present study as typical (TYP-ASTs) behaved clinically like real astrocytomas while atypical astrocytomas (ATYP-ASTs) behaved similarly to anaplastic astrocytomas. The anaplastic astrocytomas that we labelled as typical (TYP-ANAs) behaved clinically like anaplastic astrocytomas while atypical ones (ATYP-ANAs) behaved like glioblastomas. In the present study, we investigate whether some biological characteristics could be evidenced across these four groups of TYP- and ATYP-ASTs and TYP- and ATYP-ANAs. The data show that the levels of expression (immunohistochemically assayed and quantitatively determined by means of computer-assisted microscopy) of vimentin, the glial fibrillary acidic protein and the platelet-derived growth factor-alpha did not differ significantly across these four groups of astrocytic tumours. The level of cell proliferation (determined by means of both the anti-proliferating cell nuclear antigen and the anti-MIB-1 antibodies; P < 0.001 to P < 0.0001) differed very significantly between the astrocytomas and anaplastic astrocytomas, but not between the typical and atypical variants identified in each group. In sharp contrast, the levels of expression of the S100A3 and S100A5 proteins differed markedly in the solid tumour tissue in relation to the astrocytic tumour types and grades. In addition, while the levels of expression of S100A6 did not change in the astrocytic tumour tissue in relation to histopathological grade, the levels of expression of this S100 protein (but not those of S100A3 and S100A5) differed markedly in the blood vessel walls according to whether these vessels originated from low- or high-grade astrocytic tumours.

Galectin-3 and galectin-3-binding site expression in human adult astrocytic tumours and related angiogenesis

Using computer-assisted microscopy, the present work aimed to quantitatively characterize the level of the histochemically detectable expression of galectin-3 and galectin-3-binding sites in sections of a series of 84 astrocytic tumours (including 22 grade II, 21 grade III and 41 grade IV specimens) and seven non-tumoural specimens used as controls. The presence of galectin-3 and reactive sites for this lectin were monitored by means of a specific polyclonal anti-galectin-3 antibody (aGal3) and biotinylated galectin-3 (Gal3), respectively. The pattern of expression of galectin-3-binding sites is compared to the pattern of expression of laminin (a potential galectin-3 ligand) revealed using a biotinylated anti-laminin antibody (aLam). Three variables quantitatively characterizing histochemical staining reactions were evaluated by means of computer-assisted microscopy for each of the 3 probes under study (aGal3, Gal3 and aLam). The labelling index (LI) is the percentage of tissue area specifically stained by a histochemical probe. The mean optical density (MOD) denotes staining intensity. The concentration heterogeneity (CH) feature expresses the concentrational spread of individual fields. The data obtained in the present study show that: (i) white matter of a non-tumoural brain expresses galectin-3 (and also galectin-3-binding sites); (ii) the level of galectin-3 expression significantly decreases in the majority of tumour astrocytes from low to high grade astrocytic tumours; while (iii) some tumour cell clones expressing high amounts of galectin-3 emerged with increasing levels of malignancy; and (iv) the level of accessible galectin-3-binding sites was apparently not heavily modified in the course of malignancy progression. In conclusion, the results obtained in the present study show that human astrocytic tumours are very heterogenous in their galectin-3 levels of expression. If high levels of galectin-3 determine the invasiveness potential of a tumour cell, then within a heterogenous tumour the presence of even a small, but actively proliferating number of tumour cell clones expressing high levels of galectin-3 can be expected to lead to tumour invasiveness.

The influence of L-triiodothyronine, L-thyroxine, estradiol-17beta, the luteinizing-hormone-releasing hormone, the epidermal growth factor and gastrin on cell proliferation in organ cultures of 35 benign and 13 malignant human thyroid tumors

PURPOSE

To characterize the influence of six factors on human thyroid tissues at the cell-proliferation level. These six factors were the epidermal growth factor (EGF), the luteinizing-hormone-releasing hormone (LHRH), triiodothyronine, thyroxine, estradiol and gastrin.

METHODS

Forty-eight human thyroid specimens were obtained from surgical resection and maintained alive for 48 h ex vivo (in vitro) under organotypic culture conditions. These specimens comprised 35 benign cases (17 multinodular goiters and 18 adenomas) and 13 cancers. Cell proliferation in the control and treated conditions (at a 5 nM dose) was assessed by means of the thymidine labeling index, which enables the percentage of cells in the S phase of the cell cycle to be determined in accordance with autoradiographic procedures.

RESULTS

The results show that, of the six factors tested here, EGF significantly (P < 0.05 to P < 0.001) increased cell proliferation in the greatest number of cancers as compared to what happened with the remaining five. Each of these six factors significantly increased or decreased proliferative cell activity in some 10%-30% of the cases under study.

CONCLUSIONS

Triiodothyronine, thyroxine, LHRH and gastrin may increase or decrease cell proliferation in human thyroid tissues, whether benign or malignant, to the same extent as other hormones and/or growth factors such as thyrotropin, EGF, insulin-like growth factor 1, transforming growth factor beta1 and estradiol the effects of which on thyroid cell proliferation are already well documented in the literature.

In vitro motility evaluation of aggregated cancer cells by means of automatic image processing

BACKGROUND

Set up of an automatic image processing based method that enables the motility of in vitro aggregated cells to be evaluated for a number of hours.

METHODS

Our biological model included the PC-3 human prostate cancer cell line growing as a monolayer on the bottom of Falcon plastic dishes containing conventional culture media. Our equipment consisted of an incubator, an inverted phase contrast microscope, a Charge Coupled Device (CCD) video camera, and a computer equipped with an image processing software developed in our laboratory. This computer-assisted microscope analysis of aggregated cells enables global cluster motility to be evaluated. This analysis also enables the trajectory of each cell to be isolated and parametrized within a given cluster or, indeed, the trajectories of individual cells outside a cluster.

RESULTS

The results show that motility inside a PC-3 cluster is not restricted to slight motion due to cluster expansion, but rather consists of a marked cell movement within the cluster.

CONCLUSIONS

The proposed equipment enables in vitro aggregated cell motility to be studied. This method can, therefore, be used in pharmacological studies in order to select anti-motility related compounds. The compounds selected by the equipment described could then be tested in vivo as potential anti-metastatic.

Gastrin inhibits motility, decreases cell death levels and increases proliferation in human glioblastoma cell lines

Whether they are of low or high histopathological grade, human astrocytic tumors are characterized by a marked propensity to diffuse into large areas of normal brain parenchyma. This invasion relates mainly to cell motility, which enables individual cell migration to take place. The present study characterizes in vitro the gastrin-mediated effects on both the growth (cell proliferation vs. cell death) and motility dynamics of the human U87 and U373 glioblastoma cell lines. A computer-assisted phase-contrast microscope was used to track the number of mitoses versus cell deaths every 4 min over a 72-h period and so to quantitatively describe the trajectories of living U373 and U87 cells growing on plastic supports in culture media both with and without the addition of 0.1, 5, or 100 nM gastrin. While 5 or 100 nM gastrin only weakly (p < .05 to p < .01) increased cell proliferation in the U87 cell line and not in U373 one, it very significantly (p < .001) inhibited the amount of cell death at 5 and 100 nM in both the U87 and U373 lines. In addition, 5 nM gastrin markedly inhibited cell mobility in U87 (p < .00001) and U373 (p < .0001) glioblastoma models. All these data strongly suggest that gastrin plays a major role in the biological behavior of the in vitro U87 and U373 human glioblastoma cell lines in matters concerning their levels of cell motility and growth dynamics.

Determination of growth fraction and cell density to evaluate the potential growth of human oligodendroglial and astrocytic tumours

The object of this work was

PURPOSE

to develop a methodology that enables net tumour growth, a balance between actual tumour growth and tumour cell loss, to be approximately evaluated.

METHODS

The methodology proposed relies on detecting the growth fraction immunohistochemically by means of MIB-1 antibody labelling combined with cell density determination, carried out on 5-microm-thick Feulgen-stained histological sections with computer-assisted microscopy. The series investigated included 25 oligodendrogliomas (OLG-II), 9 anaplastic oligodendrogliomas (OLG-III). 13 astrocytomas (AST), 14 anaplastic astrocytomas (ANA) and 8 mixed oligoastrocytomas (OLG-AST).

RESULTS

The results show that the biological characteristics of some cases were in total accordance with their histopathological diagnoses. This was the case for the "weakly proliferating weakly dense" OLG-II and AST-II tumours, and for the "highly proliferating highly dense" OLG-III and AST-III ones. In contrast, the biological characteristics of some cases seemed to contradict the histopathological case labels. This was the case for the "highly proliferating highly dense" OLG-II and AST-II tumours, the biological aggressiveness of which would be undervalued on the basis of the morphology-based grading system alone, and also for the "weakly proliferating weakly dense" OLG-III and AST-III tumours, the aggressiveness of which would be overvalued.

CONCLUSIONS

Combining the determinations of the MIB-1 and the cell density variables appears to be satisfactory in terms of the cell kinetic characterization of glial tumours as a complement to the prognostic information given by a morphology-based grading system alone.

Characterization of astroglial versus oligodendroglial phenotypes in glioblastomas by means of quantitative morphonuclear variables generated by computer-assisted microscopy

The current WHO classification places glioblastomas in the astrocytoma category. However, whether or not glioblastomas also show oligodendroglial differentiation remains a matter of controversy. This study investigates, at the morphonuclear level, the hypothesis that some glioblastomas (GBMs) may also represent the ultimate level of malignancy in the oligodendroglial lineage. Using a series of 164 GBMs, we sought to ascertain whether any of these GBMs exhibited phenotypical characteristics that were more closely related to oligodendroglial lineages than astrocytic lineages. Phenotypical features were quantitatively determined by means of the computer-assisted microscope analysis of Feulgen-stained nuclei, a process that made it possible to quantitatively describe the patterns of the cell nuclei (and, more specifically, of their chromatin) through 16 variables, and the distribution of the nuclear DNA content (DNA ploidy) through 8 variables. The phenotypical characteristics typical of astrocytic and oligodendroglial tumors were analyzed by means of Discriminant Analysis, a statistical multivariate analysis, performed on a series of 65 astrocytic and oligodendroglial tumors. This series consisted of 14 WHO grade II and 19 grade III astrocytomas and 24 WHO grade II and 8 grade III oligodendrogliomas. This multivariate analysis enabled an accurate model to be produced that distinguished between astrocytomas and oligodendrogliomas on the basis of 5 cytometry-generated variables. This model was used to characterize the phenotype of each of the 164 glioblastomas. The results show that of these 164 glioblastomas, 6 (about 3.5%) displayed phenotypes that were very similar to oligodendrogliomas, and 141 displayed phenotypes that were very similar to astrocytomas. The phenotypes of the 17 remaining GBMs were too ambiguous to be categorized as having a pure astrocytic or oligodendroglial lineage.

Direct relationship between hormone sensitivity level and growth pattern. Evidence in 18 gastrointestinal neoplastic cell lines

OBJECTIVE

We investigated whether a relationship exists in terms of growth pattern and hormone sensitivity in 18 gastrointestinal neoplastic cell lines. Hormones studied included gastrin, epidermal growth factor, estradiol and luteinizing hormone-releasing hormone.

STUDY DESIGN

The growth patterns were assessed by means of computer-assisted microscope analysis of Feulgen-stained nuclei combined with the mathematical Delaunay triangulation and Voronoi paving techniques. This methodology enabled four variables characterizing the cell colony patterns to be computed. The information contributed by these variables was analyzed by means of discriminant analysis and the decision tree technique.

RESULTS

Each phenotype (sensitivity level) exhibited distinct growth pattern (or cell colony) characteristics in the case of each hormone and/or growth factor under study. Furthermore, the sensitivity of the gastrointestinal cell lines to a given hormone (or growth factor) appeared to be peculiar to the hormone (or growth factor).

CONCLUSION

A direct relationship seems to exist between growth pattern and hormone sensitivity levels in gastrointestinal cancers, particularly colorectal.